The Internet's Big Threat: Drive-by Attacks

Remember the days when security awareness programs only had to warn employees about website spoofing? Unfortunately, cyber-attack methods have advanced to the point where even trusted, well-known websites can silently infect users via drive-by download attacks. Last year's NBC.com incident is a good example of this growing Internet threat.

The surge in spear-phishing as the top method used by cybercriminals to gain unauthorized access to sensitive data has led to widespread implementation of end user awareness programs.

To minimize cyber risks it is essential that every employee within an organization understand that they are both an asset and a potential security liability. After instituting these programs, odds are high that most employees will know not to open the email attachment from the Nigerian lawyer who claims they are the beneficiary of a large fortune or click on an email link purporting to be from their bank, asking them to confirm their access credentials.

In the past, security awareness programs were simply required to focus on email phishing and website spoofing threats, while providing best practices, such as:

• Don't open attachments from people you don't know;

• Don't open attachments from people you know, but from whom you are not expecting to receive a particular type of file;

• Don't follow website links from unknown email senders; and

• Check the naming convention of website links to assure that they are directing you to a legitimate site.

Unfortunately, the attack on a variety of NBC websites last year proves that employees are no longer safe from drive-by malware threats when visiting reputable websites. In case of the NBC attack, cybercriminals had embedded invisible malicious elements across different websites belonging to the broadcaster. To avoid detection, these elements where periodically rotated. When a user clicked on them, it called on a RedKit to target the computer with up to three different exploit kits, including the Citadel crime ware toolkit, which is designed to steal financial information. The RedKit initially checked whether the user was running outdated versions of software or browser plug-ins. If it detected any outdated software, the vulnerability was exploited to install malicious software on the user's computer.

These type of drive-by attacks are flourishing because exploit kits that allow cybercriminals to compromise websites are readily accessible on the black market. They are very sophisticated and automated, which makes it easy for cybercriminals to scale their attacks across as many web servers as possible. Furthermore, the growing complexity of browser environments adds to the spread of drive-by downloads. As the number of plug-ins, add-ons, and browser versions grow, there are more weaknesses for hackers to exploit and add to their kit.

As a result, users who are simply surfing the Internet can unknowingly stumble upon a compromised website, which may look completely normal. As a matter of fact, cyber-attackers often specifically target well-known and popular websites, since users trust that these websites are being kept free from malware.

In addition, many drive-by attacks are launched following the release of new security patches for common applications such as Acrobat and those than run on the Java platform. Once vendors release a patch, hackers use the information to reverse-engineer the fix, uncovering the underlying vulnerability, which they then target. As a consequence, users who don't quickly update their software remain highly vulnerable to having their computer compromised by malware. This can of course lead to their personal identifiable information being stolen, activities recorded, and their computer becoming part of a botnet. Since many users fail to update the Java runtime environment installed on their computers, Java bugs remain quite popular and effective with cybercriminals.

Earlier this year, cybercriminals took drive-by attacks to the next level by front-ending their attack with robocalls. These automated phone calls urged victims to visit a leading North American wireless phone provider's website to earn hundreds of dollars in rewards. Since the website had been compromised, even cautious users were victimized, leading to stolen access credentials and subsequently account takeovers.

So what can be done to minimize the risk of these new attack techniques?

Obviously, the fundamental best practices are to keep software on endpoints up to date and also disable Java, which is one of the most popular attack vector for many cybercriminals. Beyond these essential steps, organizations should extend their diagnostic efforts. The NBC hack proved that traditional perimeter security measures often do not protect against drive-by attacks. Post-mortem analysis of the attack showed that the particular version of Citadel which was used, was only recognized by three of the 46 antivirus programs available at the time on virustotal.com.

To limit the risk of having drive-by malware attacks planted on their websites, organizations should monitor the payload of their different Internet properties, which for larger organizations can easily become a huge undertaking. By doing so, however, it is possible to detect early indicators of an ongoing attack and take steps to mitigate the threat. Since drive-by attacks are only one of many attack techniques, payload data monitoring should be part of an organization's continuous diagnostics program.

This implies an increased frequency of data assessments and requires security data automation by aggregating and normalizing data from a variety of sources such as security information and event management (SIEM), asset management, threat feeds, and vulnerability scanners. In turn, organizations can reduce costs by unifying solutions, streamlining processes, creating situational awareness to expose exploits and threats in a timely manner, and gathering historic trend data, which can assist in predictive security.